Biosorption of Cobalt (II) from Aqueous Solutions by Marine Red Alga Geracilaria sp

Subject Areas : environmental management

Akbar  Smaeli ¹ ()
Pari  Beyrami ² ()
Abdolhossein  Rostaeyan ³ ()
Ashraf  Beyrami ⁴ ()

Received: 2008-10-06 Accepted : 2008-12-27 Published : 2010-04-03

Keywords: Biosorption, red algae Gracilaria, Langmuir and Frendlich sorptio, Cobalt ion,

Abstract :

Some kinds of pollutants such as heavy metals, especially, can be removed from water and waste water by biological materials via biosorption. These heavy metals can be also recovered by adsorbents. The mentioned methods have more important advantages from some aspects such as being more economical than others. In this study marine red alga Gerasilaria sp. was used as aquatic seaweed to remove Co2+in the flow operation (packed column) of a glass column with an internal diameter of 2 Cm and the height of 35 Cm as investigated and different stages. The adsorption process was studied under affection of factors such as initial concentrations, pH, retention time (15, 30 and 45min), and adsorbent dosage (2.5 and 3.5 g) in the room temperature. The solution of Co (II) in distilled water was prepared using (Co (NO3)2,6H2O) with initial concentrations 50,100,150 mg/L. The maximum rates of uptake at pH=7 were at different degrees of 92.53%, 83.52% and 71.76% respectively. By prolonging the time of absorption from 15 minutes to 45 minutes, rate of uptake was enhanced and the highest rate was in the first 15 minutes. The final concentration of Co Ions in each sample in atomic absorption spectrometer (GBC-932), appeared that non living Gerasilaria sp. acted based on the Langmuir physics law and the kinetic studies showed that absorption of cobalt by non-living alga samples obeyed  the second degree of kinetic absorption model.